The present invention relates to a central locking system for motor vehicles and more particularly to a central locking system comprising a plurality of electric locking drives and a time control means which can be triggered by at least one manually switchable control switch on setting of a predetermined switch position, wherein the time control means switches on the locking drives for a predetermined time duration in a drive direction allocated to the predetermined switch position.
Central locking installations of this kind are known, for example from German Publication Specification No. 27 57 246. In each case a single current pulse is fed to the locking drives, which is triggered by means of the control switch and is so dimensioned in time that the locking drives are switched on for a time period sufficient either for locking or for unlocking.
Now it is sought to ensure, in central locking systems of this kind, by means of acceleration switches or the like, that in the case of an accident the central locking system is automatically controlled into its unlocking position so that helpers can enter the vehicle, even if the installation was previously locked. These attempts have shown that especially when delicate acceleration switches are used, the time control means was very frequently triggered for example when running over potholes, which led to damage to the electronics due to overloading.
The invention is directed toward improving the central locking system so that its time control means is triggered, in the case of multiple successive actuations of an acceleration switch, only on the first actuation in each case.